1. Field of the Invention
The present invention relates to powered oral care products, and more specifically, powered toothbrushes that have distinct head sections.
2. Discussion of Related Art
Toothbrushes provide many oral hygiene benefits. For example, toothbrushes remove plaque and food debris to help avoid tooth decay and disease. They remove stained pellicle from the surface of each tooth to help whiten the teeth. Also, the bristles combined with the brushing motion will massage the gingival tissue for stimulation and increased health of the tissue.
Powered toothbrushes have been available for some time. Powered toothbrushes have advantages over manual (non-powered) toothbrushes in that they impart movement to the bristles at much higher speeds than possible manually. They also may impart different types and directions of motion. These motions, generally in combination with manual movement of the toothbrush by the user, provide superior cleaning than manual toothbrushes. Typically, powered toothbrushes are powered by disposable or rechargeable batteries that power an electric motor that in turn drives the toothbrush head.
Known powered toothbrushes include a brush head with a bristle carrier portion that rotates, oscillates or vibrates in some manner so as to clean the teeth. The bristles, which typically comprise bristle tufts, are generally uniform with one end fixed into the bristle carrier portion and the other end free to contact the surface of the teeth while brushing. The free ends of the various tufts present a surface envelope that is capable of some deformation when the bristles bend. When in contact with the surface to be brushed, the bristles may deform so that the surface envelope tends to conform to the complex surface of the teeth. Human teeth generally lie in a xe2x80x9cCxe2x80x9d shaped curve within the upper and lower jaws, and each row of teeth consequently have a convex outer curve and concave inner curve. Individual teeth often have extremely complex surfaces, with areas that may be flat, concave, or convex. The more precise conformation between the bristles and the tooth surface, the more effective the toothbrush may be in cleaning, whitening and stimulating.
Known powered toothbrushes typically arrange the bristles in a compact conical or cylindrical pattern on a generally circular, disk-shaped bristle carrier. The powered toothbrush heads are traditionally compact, generally oval in shape and the heads are produced with a flat trimmed bristle pattern. Alternatively, other head shapes and bristle patterns are available.
One example of a powered toothbrush is depicted in U.S. Pat. No. 5,625,916 to McDougall, which is hereby incorporated by reference in its entirety. The toothbrush shown in McDougall has a disc-shaped bristle carrier. The bristle carrier, and thus the bristles, are driven in a vibrating or oscillating manner, which may be illustrated by FIGS. 1A-1C. A toothbrush 5 comprises a handle portion 10 at a proximal end of the toothbrush 5 and a head 11 at a distal end of the toothbrush 5. The handle portion 10 has compartments for containing a powered motor 14 and batteries 15 and 16. The head 11 includes a generally circular bristle holder 13. A rotatable shaft 12 extends from the motor 14 to the head 11. A shaft coupling 17 may be located along the shaft 12 and configured to provide for the shaft 12 to be separated at a point between the motor 14 and the head 11. This permits the shaft to be removed from the toothbrush 5, e.g., for cleaning or replacement.
The head 11 includes a post 18 that provides a rotational pivot axis for the bristle holder 13 containing bristles 19. The distal end of the shaft 12 has a journal or offset 20 that is radially displaced from the longitudinal axis of the shaft 12, which may be integrally formed therewith. The bristle holder 13 has a slot 22 that receives the offset 20. The offset 20 and slot 22 are configured so as to be oriented toward the intersection of the shaft 12 axis and the longitudinal axis of the post 18. When the motor 14 rotates the shaft 12, the motion of the offset 20 defines a circle about the shaft 12 axis and drivingly engages the slot 22 such that the bristle holder 13 vibrates or oscillates about the post 18 axis through a rotational angle A. The rotational angle A is defined by the displacement of the offset 20 from the shaft 12 axis relative to the diameter of the bristle holder 13.
Although powered toothbrushes such as described immediately above provide advantages over manual toothbrushes, they are subject to various limitations. Providing a rotating or oscillating bristle holder with a typical oblong or oval toothbrush head constrains the size of the moving bristle holder, and consequently the area of bristles available for teeth cleaning. Also, when the bristles are placed in contact with the teeth during brushing, there is less bristle contact with adjacent areas, such as the gums. Thus, while these compact bristle patterns provide for cleaning, there is minimal whitening and stimulation.
One attempt to overcome the limitations of a small powered bristle area is shown in the toothbrush of U.S. Pat. No. 6,000,083 to Blaustein et al. The toothbrush in Blaustein et al. has a bristle area and pattern similar to a manual toothbrush, but an area of the bristles has simply been replaced by a powered bristle section. The result is that the head has a powered or moving bristle section and static bristle section. The limitation of the toothbrush of Blaustein et al. is that the static bristle section provides no better cleaning, whitening or stimulation than a manual toothbrush.
International Application No. PCT/EP01/07615 to Braun GmbH discloses a powered toothbrush with two separate bristle sections that can move. Each bristle part may have a different range and type of motion. However, only one bristle part is powered. The other unpowered bristle part moves due to a resonance effect imparted by the frequency of the movement of the first bristle part.
This free resonance causes a number of difficulties. First, because any contact between the bristle parts will dampen or cancel any resonance of the unpowered bristle part, the unpowered bristle part xe2x80x9cfloatsxe2x80x9d separately from the powered bristle part.
This necessitates separation or gaps between them. These gaps expose the internal workings of the head to foreign matter such as water, saliva, toothpaste, and food particles. This foreign matter may interfere with the workings of the unpowered bristle head. For example, the unpowered bristle part is spring-loaded to assist its resonance. Foreign matter may accumulate on or around the spring, interfering with its function. In addition, food particles may remain in the head and may fester and host microorganisms, which are undesirable if not potentially harmful when introduced directly into the mouth.
Another limitation of such a design is that movement of the unpowered bristle part may be dampened by contact with the teeth, or lessened when the frequency of the powered part shifts from the resonance frequency. This can occur due to pressure imparted against the powered bristle part by the teeth or gums during brushing. Finally, the energy imparted to the unpowered bristle part is only a portion of the energy input into the powered part. Therefore, the unpowered bristle part is less effective in cleaning than the powered part, limiting the overall effectiveness of the toothbrush.
Thus, there is a need in the art for a powered toothbrush with increased effectiveness through a larger area of powered or driven bristles than known powered toothbrushes. There is also a need for a toothbrush having increased whitening and stimulation than known toothbrushes. There is further a need for such improved toothbrushes to be comparable in manufacturing and purchasing costs as known powered toothbrushes.
It is therefore a general object of the present invention to provide a powered toothbrush which avoids the aforementioned deficiencies of the known related art.
It is also an object of the present invention to provide a powered toothbrush which provides a more precise conformation between the bristles and the tooth surface.
It is further an object of the present invention to provide a powered toothbrush which results in increased cleaning, whitening and stimulation of the teeth and gums than known toothbrushes.
It is still a further object of the present invention to provide a powered toothbrush which achieves increased effectiveness by means of a larger area of powered or driven bristles than known powered toothbrushes.
It is yet another object of the present invention to provide a powered toothbrush which is comparable in manufacturing and purchasing costs as known powered toothbrushes.
Various other objects, advantages and features of the present invention will become readily apparent from the ensuing detailed description and the novel features will be particularly pointed out in the appended claims.
The present invention relates to a powered toothbrush having at least two moving bristle fields in a brush section to provide an increased moving bristle area and improved cleaning, polishing, whitening, massaging and stimulating of teeth and gums. The first bristle field includes a plurality of bristles attached to a first bristle carrier that is powered and driven in a first motion pattern by a first drive member. The second bristle field includes a plurality of brush elements attached to the brush section. An extension member having an end attached to the first bristle carrier extends outwardly therefrom and at least partially extends into the second bristle field. In this powered toothbrush, the extension moves upon movement of the first bristle carrier to move the second bristle field in a second motion pattern.
The bristles in both the first and second bristle field may be made of either an elastomeric or non-elastomeric materials or any combination thereof to provide sufficient cleaning, polishing, whitening and stimulation to the teeth and gums.
Other features and advantages of the present invention will be apparent from the foregoing detailed description when read in conjunction with the accompanying drawings.